1. Field of the Invention
The present invention relates to a brush assembly of a small motor and a method for manufacturing the same, and more particularly, to a method for precisely assembling a pair of plate brushes.
2. Description of the Related Art
Brush assemblies of small motors are commonly formed by installing a pair of plate brushes on a brush base of synthetic resin through a terminal.
Since the size of a space in which the brushes are arranged in a subminiature brush assembly must be equal to or less than 6 mm, parts of the brushes, which are very small, are spot welded to each terminal and installed in the brush base by means of caulking, thus increasing the assembly time. Also, when the brushes are spot welded to the terminal, the relative positions of the brushes and the terminal are not uniform. Therefore, the conditions under which the brushes slidably contact the commutator are not uniform and the quality of the brushes deteriorates. Also, the manufacturing cost of the brushes is high due to the price of the terminal and the time spent on processing the terminal.
To solve the above problem, it is an object of the present invention to provide a high quality brush assembly in which brushes are not separated from a commutator by making uniform the position at which the brushes are arranged and the angle formed by the brushes and the commutator where the brushes slidably contact the commutator.
It is another object of the present invention to provide a brush assembly whose manufacturing expenses are reduced by reducing the number of parts.
Accordingly, to achieve the above objects, there is provided a brush apparatus, in which means for installing a pair of brushes at a bracket through supporters connected to the brushes by integrally forming middle portions to have the shape of a sandwich so that the angle between the brushes and the commutator at a portion where the brushes slidably contact the commutator does not change is used. Therefore, it is possible to load the brushes at the bracket without using other members such as a terminal, so that the angle formed by the brushes and the commutator does not change.
There is provided a brush apparatus of a small motor, which is formed by forming a pair of brushes of a thin metal plate such that their bases are connected to each other and cutting the bases from a connector, wherein the pair of brushes are arranged at a bracket through supporters connected to the brushes by integrally forming middle portions to have the shape of a sandwich so that the angle between the brushes and the commutator in a portion where the brushes contact the commutator does not change. By doing so, the angle formed by the pair of brushes and the commutator in the position where the pair of brushes contact the commutator does not change.
To be specific, means for arranging the brushes at the bracket is preferably formed by forming the supporters including the brushes to be integral with the bracket. By doing so, there is no deviation when the brushes are installed at the bracket.
To be more specific, part of the supporter is preferably inserted into and fixed to a shaft holder in the middle of the bracket. By doing so, the strength by which the supporter is installed in the shaft holder in the middle of the bracket is improved.
The supporters can be formed of flexible synthetic resin in order to prevent the brushes from vibrating. By doing so, the vibration padder of the brushes is not necessary.
The base of the brush is preferably drawn to the outside and is preferably used as a power supply terminal. By doing so, a terminal is not necessary.
There is provided a method for forming a brush apparatus of a small motor in which a pair of brushes formed of a thin metal plate are formed such that their bases are connected to each other and the bases are cut from a connector, comprising the steps of connecting the pair of brushes formed of the thin metal plate to each other through a base in the form of a plurality of lead frames at a predetermined pitch, connecting the brushes to supporters by integrally forming middle portions to have the shape of a sandwich, and cutting the bases from the connector. By doing so, it is possible to prevent the angle formed by the brushes and the commutator from changing.
The bracket is preferably formed to be integral with the supporters in the step of forming the supporters. By doing so, it is possible to manufacture a uniform brush apparatus.